The correct answer is "239,845,499".

Solution:
Consider the numbers: 2,239,840,456 and 239,845,499.

Observe that both numbers have an unequal number of digits.

That is, 2,239,840,456 has ten digits.

239,845,499 has nine digits.

Now, the number with less digits is smaller.

So, 239,845,499 < 2,239,840,456

That is, the number 239,845,499 is smaller than 2,239,840,456.